In the Garden:Middle South
March, 2010
Regional Report

Rhododendron calendulaceum, a native plant commonly called the flame azalea, offers April flowers in a range of warm hues from pale yellow to orange, apricot, and even red, as well as colorful autumn foliage.

American Azaleas Worthy of Acclaim

If you're like me, the plant name "azalea" conjures images of evergreen shrubs that flower in vibrant Easter egg colors for a few short weeks each spring, and then fade into the background as unremarkable mounds of green for the rest of the year. Old photos of Southern landscapes often show them in bloom under live oaks hung with Spanish moss, and even many modern gardeners wouldn't consider their plot complete without a generous share of these shade-loving beauties.

But while evergreen azaleas are a long-standing and important part of our gardening culture, it's important to note that they are not native to our country. Like the so-called "Southern" camellias, they were imported to our shores from Asia hundreds of years ago.

There is a "new" azalea on the horticultural horizon receiving well-deserved kudos, however, and it turns out not to be so new after all. American azaleas (also known as native, deciduous, and wild azaleas), which have ornamented woodlands and hillsides of North America for thousands of years, are finally enjoying a bit of acclaim and wider use in home landscapes.

Fortunately, native azaleas grow as if they are right at home in many areas of the Middle South. And in many cases they are. Mainly indigenous to southeastern states, seven of the fifteen species of American azaleas grow wild in South Carolina, while twelve species can be found in Georgia.

Both American azaleas and Asian azaleas are members of the rhododendron family, but while the plants share some similarities, they are also very different. In general, Asian azaleas are spring-blooming, mounding, evergreen, and low-growing shrubs. Native azaleas exhibit few of these characteristics.

With a seven month bloom season beginning in March and ending in September, some American azalea species do flower in spring, but many bloom in summer and others bloom in fall. As the name deciduous implies, the native plants lose their leaves in autumn, and, rather than being low and dense, most American azaleas grow tall and long-limbed, with an open branching structure.

Several species of native azaleas are very fragrant and some have bright yellow flowers, while Asian azaleas are neither profusely fragrant, nor produce yellow blooms. Additionally, some American azaleas extend their ornamental season with a colorful display of autumn foliage.

Gardeners have long recognized the importance of native plants in the home landscape for their hardiness, wildlife value, and unique contribution to the ecology of local environments. American azaleas fit this profile. They provide nectar for native and migrating butterflies and hummingbirds, and often thrive in areas where exotics may not survive.

Like many other natives, they are low maintenance plants, relatively free of pests and diseases. In fact, even pruning is discouraged, as it spoils their naturally graceful form.

American azaleas should never be harvested from the wild, however, unless they are salvaged prior to land development. The survival rate of wild transplants is low and those that persist often perform poorly.

When adding native azaleas to your garden, plant them with the top of their root ball slightly elevated above the natural soil level in an area of dappled shade where they will receive some sunlight. Because their roots are shallow, it's important to keep new plants watered and mulched, and to avoid cultivation around their base. Be cautious with fertilizer, bypassing it altogether in the first year. Thereafter, use only a moderate amount of a slow-release type with micronutrients formulated especially for azaleas.